I'm gonna go ahead and bump all of these down.
In case anyone comes along later and wants to see all of them, here are the links:
Brandon, thank you for posting the pictures. I've really enjoyed looking at them!
This is Argyrodendron actinophyllum which used to be in the same genus as Heritiera. I photographed it in the Sydney RBG on a wet day.
We visited Oahu many years ago and as I remember, we went to King Kamehameha's castle. There was a garden there that his wife had created and we toured the garden. I was so impressed with the plants there, most of course were very old and some were rare. I'd never heard of a Banyan Tree at the time so I was amazed at those of course. Neat place to visit. I don't know if the garden had a name. Maybe it's the same as one of the gardens you saw.
I've been to Oahu, but only very briefly. I haven't visited any of the gardens. I would really like to do that some day. They seem to have gardens everywhere there, including:
Waimea Arboretum and Botanical Garden
Foster Botanical Garden
Ho'omaluhia Botanical Garden
Koko Crater Botanical Garden
Lili'uokalani Botanical Garden
Wahiawa Botanical Garden (different than the second one)
All the pictures in my posts were from gardens (Limahuli, McBryde, and Moir) on Kauai.
Kauai is my favorite island. Here is a picture of a Moreton Bay Fig in the Allerton Garden. Ficus macrophylla